Podcast
Questions and Answers
What is the purpose of armature voltage control during the starting of a DC motor?
What is the purpose of armature voltage control during the starting of a DC motor?
- To limit the motor current to a safe value (correct)
- To decrease the back emf during starting
- To increase the motor current for faster starting
- To prevent sparking at the commutator
How does adding a variable resistance in series with the armature circuit affect the motor's operation?
How does adding a variable resistance in series with the armature circuit affect the motor's operation?
- It limits the armature current at a safe value
- It has no effect on the motor's operation
- It decreases the no-load speed
- It increases the speed drop during loading (correct)
What happens if a DC motor is started with full supply voltage across its terminals without any current limiting method?
What happens if a DC motor is started with full supply voltage across its terminals without any current limiting method?
- The motor will not start at all
- A very high current will flow, potentially damaging the motor (correct)
- The motor will start smoothly without any issues
- The back emf will increase, reducing the starting current
What is the effect of decreasing the variable resistance in series with the armature circuit as the motor accelerates?
What is the effect of decreasing the variable resistance in series with the armature circuit as the motor accelerates?
Which method is normally used to control the speed of a DC motor during operation?
Which method is normally used to control the speed of a DC motor during operation?